In oil and gas production, it is sometimes beneficial to stimulate a reservoir by pumping in high pressure fluids and particulates, such as sand. In order to do this, one or more tubular sections of a tubular installed in the well may need to be isolated for a period of time and re-opened so the well can be produced. Some current methods of isolation use a frac plug and a sealing ball. A frac plug is a hollow, cylindrical plug that can be installed in the tubular section(s) selected for isolation within the well. The sealing ball then seats in the frac plug to stop fluid flow through the frac plug location and isolate the selected tubular section(s).
Currently, frac plugs are built around a central mandrel. Typically, the central mandrel is then held in place within a tubular section using upper and lower slips. However, such designs may shift within the tubular section when a sealing ball is installed. Additionally, the sealing element is positioned between the slips. This arrangement may prevent the sealing element from fully compressing if the slips become fully engaged prior to full compression of the sealing element. Further, current frac plugs may allow extrusion of the seal during stimulation of the reservoir, or move as the plug is milled or ground to allow production.
What is needed, therefore, is a frac plug that can maintain the desired position within the tubular section, ensure full compression of the sealing element, and remain in place during milling or grinding operations.